The proposed Phase II effort is to build two complex compound prototypes to remove 4.6 kW heat from laser diodes at 280K to 300K. The prototype will be delivered to MDA upon completion of the Phase II project. The technology is based on a proven solid-vapor sorption complex compound technology used in refrigeration and freezers. The complex compound technology has the following features: A high energy to mass density, as complex compounds use high solid-vapor phase change energy to store, remove and reject energy. Passive transport of energy between two points, as ammonia vapor is transferred between two sorbers containing the complex compounds. The transport process only depends on the sorber's temperatures and choice of complex compounds. Gravity independent, as only solid salts and vapor ammonia are used. Thermal energy storage capability, complex compound sorption process can store energy indefinitely for future removal without power requirements or performance degradations. Phase I effort showed both the feasibility and advantages of using complex compound systems over the existing pumped loop systems. Testing showed several complex compounds are viable candidates. Phase II effort will continue the development by defining the detail design of sorbers and overall system. This design will be then tested and refined in two prototypes to be delivered to MDA.